Tableted detergent and detergentbleach compositions comprising alkyl orthophosphate salts



United States Patent 3,329,615 TABLETED DETERGENT AND DETERGENT- BLEACHCOMPOSITIONS COMPRISING AL- KYL ORTHOPHOSPHATE SALTS Robert S. Cooper,Park Forest, and Allen D. Urfer, De-

catur, Ill., assignors to Staufier Chemical Company,

New York, N.Y., a corporation of Delaware No Drawing. Filed July 23,1964, Ser. No. 384,794

. 1 Claim. (Cl. 252-99) This invention relates to tableted cleaningcompositions comprising water soluble alkyl orthophosphate salts and amethod of producing the same.

Today, tableted cleaning compositions are familiar articles in themarketplace; among their advantages are obviation of the need formeasuring cups and elimination of the usual spillage problemsencountered with granular cleaning compositions. In the manufacture oftableted cleaning compositions by compression of dry particulatecompositions two principal methods have evolved: the first, and by farthe more frequently used, comprises tableting at high pressure acleaning composition comprising at least one hydratable compound(usually an inorganic salt of a phosphorous acid) and thereafterhydrating this hydratable compound to increase surface strength andabrasion resistance of the tablets. The second method involves addingcertain binding agents, e.g., talc and starch, and water to the cleaningcomposition before tableting to improve cohesion in the final tablet.Although these methods have been successful in the past, they haveinherent disadvantages and limitations which will be explained morefully hereinafter.

Most cleaning compositions, and in particular heavy duty detergentcompositions comprising alkyl aryl sulfonates, show a tendency to stickto die surfaces when the same are used to compress the composition intotablet form. Where significant amounts of water are added to, or presentin, the compositions before tableting, sticking becomes even morepronounced. In some instances it is necessary to include water in thecleaning composition before tableting to insure that the tablets willhave adequate strength. Sticking, of course, causes breakage of tabletswhen the dies are separated, as well as mottling of tablet surfaces. Onthe other hand, the addition of water to finished tablets to increasethe strength thereof tends to decrease the rate at which the tabletswill disintegrate in water. Also, the addition of water or a surfaceactive agent to a cleaning composition comprising a bleaching agenteither before or after tableting, can severely diminish the activity ofthe bleach. It is therefore selfevident that many tableted cleaningcompositions should contain as little water as possible commensuratewith high strength and rapid distintegration properties. Binding agents,such as talc and starch, which are presently used in some hard surfacecleaners, tend to diminish sticking and reduce the amount of waternecessary to obtain tablets with acceptable physical properties.Unfortunately, the binders used heretofore generally do not contributeto the detergent or building properties of the cleaning compositionsand/or are not totally water soluble. Tablets containing such bindersproduce turbid solutions which are unsuitable for the laundering ofclothes and the like. In laundering operations insolubles are obviouslydifficult to rinse out of clothing.

It is an object of this invention to provide a process for producingdetergent and detergent-bleach composi- ICC tions which may be tabletedto yield tablets of high quality and strength and having a rapid rate ofdisintegration in water.

It is another object of this invention to furnish tableted compositionscomprising inorganic bleaching agents togetlliler with surface activematerials compatible therewit It is still another object of thisinvention to furnish a process for producing tableted detergent anddetergent bleach compositions comprising novel binding agents which aretotally water soluble.

It is still a further object of this invention to furnish tableteddetergent and detergent bleach compositions containing surface activecompounds which provide binding action for said compositions.

It is yet another object of this invention to furnish home andcommercial cleaning com-positions comprising bleaching agents togetherwith compatible surface active compounds.

Other objects will become apparent as the disclosure proceeds.

We have now discovered that certain monoand dialkyl orthophosphate saltsmay be included in tableted cleaning compositions to yield tabletshaving high strength and good disintegration properties and which do notstick to dies during formation. A number of important advantages followfrom using the alkyl orthophosphate salts: for example, their use willsubstantially reduce or obviate entirely the need for'water or otherbinders in producing firm, non-flaking tablets. Unlike most of thewell-known prior art synthetic detergents, such as sodium lauryl sulfateand sodium dodecyl benzene sulfonate, the monoand diakyl orthophosphatesof the invention (some of which are excellent detergents) are highlycompatible with chlorine bleaching agents. Some further advantages ofusing the alkyl orthophosphate salts include a more rapid rate ofdisintegration of tablets and high degree of pourability of the cleaningcomposition prior to tableting. Regarding the latter, cleaningcompositions comprising the alkyl aryl sulfonates of the prior art oftenwill not flow freely through feed hoppers and the like prior totableting.

The alkyl orthophosphates suitable for use according to the presentinvention are the water soluble salts of monoand dialkyl orthophosphatesin which the organic portion of the molecule comprises a total ofbetween 6 and 26 carbon atoms per molecule. It is common in the art tospeak of detergent compounds in terms of their salts and it is wellknown that salts of various detergents may be prepared by reacting thecorresponding acid material with sodium, lithium, or potassium hydroxideor carbonate. Although the alkali metal salts of the orthophosphates ofthe invention are preferred, ammonium and amine salts are also useful.All of the aforementioned compounds are waxy, water soluble solids whichimpart a high degree of binding action when added to dry particulatecomposition. A group of alkyl orthophosphates which are preferred foruse in the present invention are those in which the alkyl group containsa total of between 18 apd 22 carbon atoms, for example, sodium2-ethylhexyl decyl orthophosphate, sodium dinonyl orthophosphate,potassium di(n-decyl)orthophosphate, sodium didecyl orthophosphate,sodium methyl eicosyl orthophosphate. These preferred compounds all haveexcellent detergent properties and thus serve the dual purpose ofbinding the tableted composition and enhancing its detergent action.

The cleaning compositions of the present invention may be divided intotwo principal categories: (a) those which contain no chlorine bleachingagents and (b) those which do contain chlorine bleaches. Where usedherein the expression detergent tablets refers generally to bleach-freetablets such as those used for laundry detergents, suds boosters, andhard surface cleaners. In its broadest sense, the term may includetablets which contain little or no detergent (surfactant). Likewise, theexpression detergent-bleach tablets refers to those cleaningcompositions which contain chlorine bleaching agents, and in a broadsense will include tablets which contain little or no surfactant. Thealkyl orthophosphates of the invention are suitable for use in bothdetergent and detergent-bleach tablets.

The alkyl orthophosphate salts disclosed herein are useful in thepreparation of tableted compositions containing any of the standardcleaning ingredients known heretofore in this art. Principal among thenecessary detergent tablet ingredients are the surfactant and builder.The popular known builders are the alkali metal metaphosphates,pyrophosphates, and triphosphates, all of which will be referred toherein generically as condensed phosphates. Typical examples of widelyused condensed phosphate builders are sodium tripolyphosphate,tetrasodium pyrophosphate, and tetrapotassium pyrophosphate. Thesurfactant may be any of the known synthetic anionic detergents such asthe alkyl aryl sulfonates or the nonionic detergents such as thosecontaining a water solubilizing polyoxyethylene group in chemicalcombination with an organic hydrophobic compound such aspolyoxypropylene, alkylphenol, etc. A third important component of adetergent composition may be referred to as auxiliary material. Theauxiliary material may be inorganic and/or organic. Among theconventional inorganic auxiliary material ingredients are the variousbleaches, binders, alkayl metal silicates, carbonates, orthophosphatesand sulfates. Among the organic auxiliary materials areanti-redeposition agents sodium carboxymethyl cellulose) sudsbuilders,%g tarnish inhibitors, foam stabilizers, binders, oamingagents, whiteners, preservatives, perfumes, bacteriostatic agents,coloring matter, and the like.

Regarding the proportions of the foregoing ingredients, tableted laundrydetergents will normally contain more surfactant and builder and lessauxiliary material than hard surface cleaners. Tableted laundrydetergents will normally comprise between 25% and 90% by weight,preferably between 35% and 70% builder. Also the tableted laundrydetergent will necessarily comprise between 3% and 25%, preferablybetween 5% and by weight of a surfactant. Tableted suds boosters on theother hand will comprise predominantly a builder such as sodiumtripolyphosphate and possibly a minor amount of surfactant and auxiliarymaterial. Most straight bleach tablets (those formulated specificallyfor bleaching purposes only) contain in addition to the bleaching agenta predominant proportion of either a filler, i.e., sodium sulfate,sodium corbonate, sodium silicate, or trisodium phosphate, or aninorganic alkayl metal condensed phosphate, i.e., sodiumtripolyphosphate, potassium tripolyphosphate, tetrapotassiumpyrophosphate, or tetrasodium pyrophosphate. When the tablet contains alarge proportion of condensed phosphate it is more correctly referred toas a bleach-builder or bleach-suds booster tablet since the condensedphosphate will furnish building action. The straight bleach tablet mayalso contain a minor proportion of surfactant, optical brightener,sodium carboxymethyl cellulose, binder, or the like. In accordance withthe invention a typical bleach tablet for home laundry or commercialbleaching operations will comprise between 50 and 90 parts by weight ofcondensed phosphate or filler, 10 to 50 parts bleach compound, e.g.,

potassium dichloroisocyanurate, and l to 20 parts, preferably 2 to 10parts, of one or more of the alkyl orthophosphate salts.Detergent-bleach tablets will comprise the same proportions of builder,surfactant, filler and auxiliary materials described hereinabove forordinary detergent tablets, except that from about 1% to 25% of thebuilder and/or filler is replaced by a bleach compound.

The granular cleaning compositions to be tableted in accordance with theprocess of this invention may comprise a uniform physical mixture of theindividual components or a homogeneous mixture such as that obtained byspray drying or roll drying a slurry of the ingredients. In a preferredembodiment of the process (applicable only to tableted bleach-freedetergents) the orthophosphate salts are added in the last step of theprocess prior to tableting. The same procedure is preferred whenpreparing bleach-containing tablets, except that the bleach must beadded after any water is added. In such manner any water added prior tothe addition of the bleach may be absorbed by the other ingredients ofthe granular mixture, thereby reducing its availability to react withthe bleach. The alkyl orthophosphate salt may be added directly to theother ingredients or, preferably, mixed with water to form a 40% to 70%slurry which may then be sprayed upon a bed of the agitated material.Significantly, the alkyl orthophosphate salt tends to disperse moreuniformly on or among the granular particles when applied from anaqueous slurry than when admixed as a dry component.

The granular mixture may be compressed at a pressure between 3 poundsper square inch and about 1000 pounds per square inch, depending uponthe tableting characteristics of its particular ingredients. Tabletshave been prepared under even higher pressure, but these generally haveprohibitive hardness and disintegrate only slowly in warm water. As arule tablets designed for hard surface cleaning and bleach uses areformed at relatively high pressures, preferably between about and 500pounds per square inch, while detergent tablets and detergentbleachtablets require less pressure, preferably 25 to 200 pounds per squareinch. Further, the greater the amount of alkyl orthophosphate saltpresent in the composition to be tableted, the lower the pressurerequirements. Any of the known methods for curing the tableted productsmay be employed by the present invention. Except for those which containbleach, the tablets may be subjected to a water spray or steam treatmentafter compression to harden the tablet surface. Alternately, the tabletsmay be heated for a time after compression to improve strength. Bothheat treatments and water treatments are generally undesirable withbleach-containing tablets since such tend to degrade the bleach.

The proportion of alkyl orthophosphate salt required in any of theaforesaid cleaning compositions will depend upon the particular compoundselected. While all of the alkyl orthophosphate salts will furnish somebinding action and some detergent action there are large differencesbetween individual compounds and these differences correlate directlywith differences in the number of carbon atoms contained in the alkylradicals. There is a gradual increase in binding action as the number ofcarbon atoms increase from 6 to 26 while a more pronounced and suddenchange in detergent performance is observed when the total number ofcarbon atoms exceeds 17. Detergency decreases after 22 carbons althoughbinding action continues to increase with the higher molecular weights.

As a means of expressing the performance of various surfactants in builtdetergent mixtures, we prefer to use a mathematical expression of thesevarious characteristics to provide what may be termed a PerformanceIndex (P.I.). This index is defined as follows:

Max. Detergency-Builder Detergency wherein P1. is the Performance Indexand is calculated by taking the maximum detergency obtained using agiven surfactant formulation, minus the detergency of the builder used,and then dividing this value by the minimum use level of the surfactantwhich will produce the indicated maximum detergency value for themixture in question. The following are Performance Indexes for some ofthe alkyl orthophosphate salts of the invention.

invention for the sole pur- When used by the present the tabletedcleaning pose of providing binding action to composition, invention willcomprise between about 0.1% and by weight of the composition, andpreferably between 2% and 5% by weight. When used to provide bothdetergent and binding action the compounds having between 18 and 22carbon atoms may be included in higher proportions usually between 0.1and 25% by weight of the cleaning compositions, preferably between 2 and15%.

The alkyl orthophosphate salts may also be used in combinations with theknown anionic and nonionic surfactants of the prior art since in allproportions the former are compatible with such surfactants. This isparticularly the alkyl orthophosphate salts of the present important incertain laundry detergent tablets where inclusion of a sufficientquantity of alkyl orthophosphate salt to provide good detergent actionwould yield a somewhat hard, slowly water soluble tablet. A1; detergenttablet comprising 1% to 10% oghgphosphate (as a combination surfactantand bin er) plus 5 0 togL5% isodium lauiyl sulfateit common surfactant)is especially suitable for laundering purposes.

It should be especially noted that the principal prior art surfactantsand chlorine bleaches are mutually incompatible, that is, the chlorinereacts with the surfactant resulting in a loss of detergent propertiesas well as bleaching potential.

Although it is one object of this invention to reduce the amount ofwater needed to furnish satisfactory binding power in tableted cleaningcompositions, a small amount of water may be added to the ingredientsbefore tableting or thereafter to harden the surface thereof. Where asignificant amount of alkyl orthophosphate salt is used, usually 3-5% byweight of the tablet, or more, little or no water is needed to produce astrong tablet. Some water, however, may be helpful where it is desirableto use less of the phosphate binder or where it is preferred to add thephosphate binder in a water slurry or solution which is sprayed upon theother granular materials.

3 About 3 to 5% by weight of water may be added to the ingredients of astraight bleach composition without markedly degrading the addedchlorine bleaching agent.

Slightly higher amounts of water may be added when formulating laundrydetergent-bleach tablets. Any water added to the ingredients before thebleach will be adsorbed on the dry granular particles and hence will notreadily react with the bleach. On the other hand, it is generallyundesirable to add water to the surface of sodium didecyl the tablets(containing the bleaching agent) since the added water may react withand degrade the bleach.

The following specific examples will further illustrate theabove-mentioned principles of the invention and in particular thespecific results which may be obtained by using the alkyl orthophosphatesalts of the present invention in specific detergent formulations. Theseexamples are intended to be illustrative only and no limitations shouldbe implied therefrom,

Example 1 To determine the stability of the alkyl orthophosphate saltsin the presence of organic chlorine bleaching compounds an alkalinesolution containing a popular chlorine bleaching compound and a smallamount of alkaline material was prepared. To this solution was addedvarious prior art surfactants as well as an alkyl orthophosphate salt ofthe invention (sodium didecyl phosphate). The stability of eachsurfactant was determined by measuring the surface tension of itssolution periodically.

(Note: as the surfactant is inactivated by the bleach the surfacetension increases.)

ALKALINE SOLUTION Percent Soda ash 5.0 Potassium dichlorisocyanurate 5.0Water 90.0

TABLE I,SI'RFACTA.\T STABILITY IN THE PRESENCE OF ORGANIC CllLORlNEBLEACUING COUPOI'NDS Surface tension in Conccntradyncs/cm. Surfactantadded to solution tion of surfactant.

p.p.iu. Initiilly After 20 days Sodium didecyl phosphate... 50 26.0 20.0Sodium lauryl sulfate H 50 28. 9 55. 8 Sodium dojecyl benzene sulfonate50 27. 0 55. 0 lsooctyl phenyl polyethoxyethanol 50 31. 3 6G. 0 Dioctylester of sodium sulfosuccinie acid 50 25. 5 41.4 Fatty acid alkanolamide5U 27. S 6%. 6 Polycthenoxy tallitem. 37. 6 (32. 2 Sodium Q-ethylhexylsulfate 47. 8 72. 0 Polyoxyetliylene ester of fatty acld 100 as. 9 60. 9Alkyl polyoxyethylenc ethers. 50 3t. 6 63. 2 Polyoxyethylene laurylether. 50 28. 1 50. 5

Example 2 Granular detergent-bleach compositions were prepared by mixingthe following ingredients in a Hobart mixer:

Percent by weight Sodium tripolyphosphate 48.0

Sodium sulfate 24.0

Water 4.5 Surfactant (specified in Table II, infra) 7.5

Potassium dichloroisocyanurate 16.0

The sodium tripolyphosphate, sodium sulfate, surfactant and water werefirst thoroughly intermixed after which the potassiumdichloroisocyanurate (bleach) was added, with mixing. The mixture wasthen fed to a Stokes Single Punch R-4 Model tableting machine where itwas compressed in the form of tablets at a pressure between )0 00 oundsper square i bsequent to compression the ta e s were a owed to stand atroom tempera- 7 ture (about 75 F.) and 70% relative humidity for fortydays. At ten and forty days the tablets were analyzed to determine thepercentage of original chlorine still available. The results of thesetests are presented in Table II.

the surfactant, immediately prior to tableting. The tablets were neithertreated nor cured in any manner after tableting, but rather, were storedat room temperature and 75% relative humidity for thirty-five days todetermine TABLE III.LI1\1ITS OF ALKALINITY IN TABLETED CHLORINEBLEACIIES [Formulations (Percent by weight)] Ingredients 1 2 3 4 5 6 l 7i 8 9 10 ll 12 NQ;SO 72.5 30.0 20.0 11.0 29.0 1 I S'Illtgranularl 351543. s l 30. 5 as. 5 as. 5

Sodium dldEC} p 7.5 7. 7.5 7.5 7.5 7.5 7.5 7. 5

Potassium dichloroisocyanurate 40. 0 20. O 20. 0 20. 0 20.0 20. 0 20.020. 0 Percent of ori inal active Cl after days at RT. and 75% RH 98 9893 90 95 98 87 83 97 48 70 Percent of Original active Cl after 35 daysat R.T. and 75% RH 90 97 93 91 S1 86 9G 97 85 78 60 3 N.A.

Condition of tablets after 35 days Good Flaky Good Good Fair Good HardGood Good Soft Poor Disintegrated l STPP-sodium tripolyphosphate. 1TSlP-tetrasodium pyrophosphate. I Tablet disintegrated completely-nochlorine analysts.

TABLE II.CIILORINE BLEACH STABILITY IN TIIE PRES- ENCE OI VARIOUSSI'RFACTANTS 'A P7 )s-tlecyl alcohol reaction mixture containing bothinonodeeyl and didecyl esters.

the loss in chlorine during such time. At ten days and thirty-five daysthe percentage of available chlorine, compared to the originallyavailable chlorine, was determined. The formulations used and theresults of the storage tests are summarized in Table III.

Example 4 Employing the procedure described in Examples 2 and 3 above, aseries of detergent-bleach tablets containing a high proportion ofbleach were prepared. Two anionic surfactants, i.e., sodium dodecylbenzene sulfonate and sodium lauryl sulfate and one nonionic surfactant,i.e., isooctyl phenyl polyethoxyethanol were compared to sodium didecylorthophosphate in these tests. The didecyl phosphate salt was added tothe other ingredients as an aqueous slurry while the sodium dodecylbenzene sul- TABLE I\'.CIILORINE STABILITY 1N DETERGENT-BLEACH TABLETSCONTAINING VARIOUS SURFACTANTS [Formulations (ingredients in percent byweight)] Ingredients NaDlJBS 3 (dry) NaDDBS i aqueous slurry) Isooclylphenyl polyethoxvethanol i Sodium lauryl sulfate (drv). l

Optical brightener Water.

Potassium Percent chlorine (active) remaining after 15 days at R.T. and70; R.ll Percent chlorine (active) remaining I after today's at R.T.and757 .11..

3 ounce 59 s9 s0 62 7s 72 7o 70 i s Example 3 To ascertain the effect ofalkalinity on the chlorine stability of tablets containing the alkylorthophosphate salts, tablets were prepared containing some of the morecommon commercial ingredients. The alkaline ingredients chosen weresodium tripolyphosphate (pH=9.7), tetrasodium pyrophosphate (pH=10.2),soda ash (pH=11.4), and sodium silicate (pH=l2.3). Sodium sulfate, whichis nearly neutral in a 1% solution, was also used as an ingredient. Thegranular ingredients were intermixed and tableted in essentially thesame manner as the tablets described in Example 2 with the exceptionthat the orthophosphate surfactant-binder was added as a 65% aqueousslurry and was sprayed upon the pre-mixed dry ingredients. The potassiumdichloroisocyanurate was added after fonate was added both dry and as a60% aqueous slurry. The nonionic surfactant and sodium lauryl sulfatewere both added dry to the other dry ingredients. In a first series oftests the tablets, after compression, were held for fifteen days at roomtemperature and 70% relative humidity. A second series of tests involvedholding the tablets at room temperature and 75% relative humidity forforty days. At the end of each storage period the tablets were inspectedfor physical condition and were analyzed to determine the amount ofactive chlorine remaining. The results of these tests are set forth inTable IV.

Example 5 The binding action of the alkyl orthophosphate salts intableted suds booster formulations and hard surface cleaner formulationswas determined. The phosphate salts tested contained alkyl radicalsranging from 8 to carbon atoms and included the mono-esters, di-esters,and mixed mono-di esters. Tablets were prepared in accordance with theprocedure described in Examples 2 and 3 and were allowed to stand fromone to two hours after compression before testing. The suds booster andhard surface cleaner formulations used were as follows:

Tablets prepared from the ingredients shown in each of the aboveformulations were tested for impact strength (drop test) and compressionstrength (crushing test). The drop test consists of dropping the tabletsthree feet to a concrete floor: results are evaluated by visualobservations of the tablet after being dropped; in general, a tabletwhich does not crumble after being dropped is considered satisfactorywhile a tablet which crumbles or disintegrates into a powder does nothave the physical characteristics acceptable for a commercial product.Crushing strength is a measure of the weight required to crush a tabletstanding on its edge. In this test a tablet (1.75 inches in diameter and0.72 inch thick) is rested vertically on a horizontal fixed support anda varying weight load is applied tangentially (through the verticalaxis) to the top edge of the tablet. A crushing strength of over about2000 grams, and preferably between about 2500 grams and 4000 grams, isconsidered satisfactory for tableted products. Tablets having a crushingstrength below about 2000 grams readily disintegrate or flake duringhandling while tablets above about 4000 grams tend to disintegrate tooslowly when placed in water. The impact strength and compressionstrength of various tableted suds boosters (A) and hard-surface cleaners(B) are presented in the following table.

TABLE V.-PHYSICAL CHARACTE RISTICS OF TABLETED Although not shown in theabove table, all of the tablets containing the alkyl orthophosphatesalts disintegrated rapidly in a large volume of warm water (120 F.).Further, no difference was observed in the rate of disintegrationbetween tablets containing a small amount of water as a binder and thosecontaining the alkyl orthophosphate salts.

The cleaning compositions described and tested in accordance withExamples 2 through 5 were evaluated by standard laboratory cleaningprocedures to determine their suitability for each disclosed use. Toillustrate, standard laundering tests were accomplished to evaluate theefficiencies of those compositions formulated for laundering operations,while the straight bleach formulations were evaluated for bleachingcapacity. These tests indicated that all of the compositions comprisingthe alkyl phosphate salts of the invention were equivalent or superiorin overall cleaning power to similar compositions (where such exist)presently manufactured and marketed for the same uses. Some of thecompositions included for comparison purposes, e.g., those seriouslydegraded by the action of the surfactant on the bleach and vice versa,were, of course, somewhat inferior and/or unsuitable for the intendeduse.

Another feature of tableted cleaning compositions containing the alkylorthophosphate salts, especially those which have high surfactantproperties, is that the alkyl orthophosphate salt is readilybiodegradable. Considerably public concern has been expressed in recentyears regarding the amount of detergent present in surface water andsub-surface waters. Of particular concern is the fact that many of thewidely used alkyl benzene sulfonate and sulfate materials are notreadily biodegradable.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations are to be derivedtherefrom, as modifications will be obvious to those skilled in the art.

We claim:

A bleach composition in the form of a water soluble tablet having highimpact and crushing strength and rapid disintegrability in warm watercomprising the following ingredients in the indicated proportions:

Parts by weight Sodium sulfate, sodium tripolyphosphate, tetrasodiumpyrophosphate, sodium carbonate -90 Sodium didecyl phosphate 2-10Potassium dichloroisocyanurate 10-50 (References on following page) SUDSBOOSTERS AND HARD SURFACE CLEANERS CONTAINING ALKYL PHOSPHATE BINDE RSDrop Test 1 Crushing Test, gms. Binder used 1 (Number of C atoms) A B AB Water 5 3 1, 800 1, 900 Sodium dibutyl phosphate (8).... 5 5 1, 5002,200 Sodium monooctyl phosphate (8) 4 2 3, 000 3,200 Sodium monodioctyl phosphate (average 12) 3 2 3, 300 2, 700 Sodium dioctylphosphate (16)... 2-3 2 3,800 3,800 Sodium didecyl phosphate (20) 2 1 3.800 3, 900 Sodium mono dllauryl phosphate (average 18).. 2 1 3, 700 4,200 Sodium mono di tridecyl phosphate (average 20). 2 1 4, 3, 500 Sodiummono stearyl phosphate (18) 3 2 4, 000 4, 200

into several pieces; 5=tablet crumbles into powder.

Water used at 5% by weight-a1kyl phosphates in 50% aqueous slurry(phosphate=2.5%

of total tablet ingredients).

1 1 12 References Cited 3,120,378 2/1964 Lee et a1. 252-95 1 3,172,8593/1965 Percival et a1. 252-138 XR UNITED STATES PATENTS LEON D. ROSDOL,Primary Examiner.

2,005,619 6/1935 Graves 260-4613 2,656,372 10/1953 Ernst 6:61. 260-461 5JULIUS GREENWALD Exammer- 3,081,267 3/1963 Laskey 252-135 J. T. FEDIGAN,Assistant Examiner.

